Thread: Mismatch tyres

What size are you considering? I don't recall another size that would be close enough.

I think the answer is - you can. But it is not good practice, and is almost certainly illegal in most, if not all, jurisdictions.

But, provided the difference in rolling radius is small, and the treads are similar, you will almost certainly get away with it. Mechanically, different tyre sizes mean the centre diff is continually compensating for this, but provided that the difference is small, it will be less than the compensation happening all the time from turns. Tread differences can result in some unexpected handling issues, but providing you never drive close to the adhesion limits these should not be noticed. Of course, if the difference in rolling radius is enough to give rotation differences that trigger the ABS, then you really have problems (very unlikely).

You should never have different tyres on the same axle.

a differential's job is to enable the driven axles wheels to rotate at different speeds and will happily do it all day.

I currently have 3 different tyres on my car due to punctures/blowouts out bush and having occurred at different times.....you can see the difference in diameter when you stand them side by side.....it has made no noticeable difference to driving.

it is when you are in 4wd that a significant difference in rolling radius creates windup. if youre really concerned about tyre management keep the equal sizes on the rear . Its not until you want to use 4wd that it may give you concern and on loose dirt roads shouldnt bother you.

in 4wd low I can hear whichever tyre is out of whack but that changes as soon your direction changes.

I'm not condoning driving on uneven tyre diameters in any shape or form , just stating I'm managing my situation until the bloody things are worn.

Originally Posted by INDABA

I am not sure how to word this, BUT,,,,
Do I have any leeway with different tyre sizes on my disco
IE It has 245-70-16 on it now Can I run anothe size that is close to this ?
My understanding is that I cannot, will the diff take out a small difference

Many thanks

Hmmmm... Do you actually mean "can I run some different size tyres on my car along with what's already on there?"

E.G. 245/75/16 on the front
245/70/16 on the back

Or .. Do you mean "can I change all my tyres to (for instance) 245/75/16“?


You can definitely change all the tyres to a different size, as long as they fit and have the correct load rating.

Running mismatched sizes front to rear or across an axle will mean you no longer have insurance, I'd only do it to get out of a jam.

Originally Posted by ramblingboy42

a differential's job is to enable the driven axles wheels to rotate at different speeds and will happily do it all day.

I currently have 3 different tyres on my car due to punctures/blowouts out bush and having occurred at different times.....you can see the difference in diameter when you stand them side by side.....it has made no noticeable difference to driving.

it is when you are in 4wd that a significant difference in rolling radius creates windup. if youre really concerned about tyre management keep the equal sizes on the rear . Its not until you want to use 4wd that it may give you concern and on loose dirt roads shouldnt bother you.

in 4wd low I can hear whichever tyre is out of whack but that changes as soon your direction changes.

I'm not condoning driving on uneven tyre diameters in any shape or form , just stating I'm managing my situation until the bloody things are worn.

Perhaps worth pointing out that the OP is talking about a Disco, which is full time four wheel drive. No mention of which model - the possible issues with the ABS and traction control increase as you get newer.

Yes I have a fulltime 4wd disco
Just one tyre different on the axle, not a large difference in size, but still a different size


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Originally Posted by INDABA

Yes I have a fulltime 4wd disco
Just one tyre different on the axle, not a large difference in size, but still a different size


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But which model, D1 wont be any issue if they are close but D2/3/4/5 will have issues with odd sizes.

My oversight, I should have stated that it was a 98 D1